1. Field of the Invention
The present invention relates to a hearing aid device of the type known as an xe2x80x9cin the earxe2x80x9d (ITE) hearing aid, that can be directly inserted in the ear as well as to a xe2x80x9cbehind the earxe2x80x9d (BTE) hearing aid which has an otoplastic that is inserted in the ear, the hearing aid having at least one input transducer, a signal processing unit, an output transducer, and a ventilation channel.
2. Description of the Prior Art
The ventilation channel of a hearing aid device that can be directly inserted in the ear or of a hearing aid device having an otoplastic that can be worn in the ear serves the purpose of ventilating the ear channel, compensating the atmospheric pressure or reducing the closing effect (occlusion effect). An optimally large cross section of the ventilation channel is desired for this purpose. The ventilation channel, however, represents an acoustic bypass to the signal path via the input transducer, the signal processing unit and the output transducer of the hearing aid device, so that functions of the hearing aid device, such as a particular directional effect or a background noise reduction, can become ineffective, particularly in a loud sound situation. Moreover, feedback between the output transducer and the input transducer particularly arise in sound situations with a low level of the input signal and a high amplification of the hearing aid device, which is caused by dynamic compression, via the ventilation channel. This effect is also dependent on the cross-section of the ventilation channel. A desire to make the ventilation channel as small as possible results from these reasons. Therefore, the diameter or cross-sectional size of the ventilation channel represents a compromise between the wearing comfort and performance features of the hearing aid device. It is normally adjusted during the adaptation to the hearing aid device by means of inserting sleeves with differently sized bores for narrowing the ventilation channel to an appropriate size.
German OS 40 08 982 discloses a hearing aid device with a ventilation channel and for adaptation of the ventilation channel, a locking means In the ventilation channel for altering the cross section of the ventilation channel. The cross-section thereby can be varied between a maximum size and a complete closure with the aid of a screw driver. This adjustment possibility is carried out by the acoustician, who conventionally adjusts the opening of the ventilation channel such that transmission is free of feedback with the adapted hearing aid device In normal sound situations.
An object of the present invention is to improve the wearing comfort and the performance features of a hearing aid device having a component adapted on insertion in the ear, this component having a ventilation channel.
This object is achieved in a hearing aid device that can be directly inserted in the ear or worn in the ear with an otoplastic, having at least one input transducer, a signal processing unit, an output transducer, a ventilation channel and a moveable element for adjusting the cross-sectional size of ventilation channel operated by at least one electrical and/or magnetic miniature drive. The hearing aid device can be an ITE hearing aid, in which case the ventilation channel is in the hearing aid housing, or a BTE hearing aid, in which case the ventilation channel is in an otoplastic that is inserted in the ear.
Valves, pins, slides, flaps, adjoining discs with respective openings therein that are rotatable relative to one another, are suitable elements for adjusting the cross-sectional size of the ventilation channel, particularly by constricting or dosing the ventilation channel. The invention also encompasses a parallel arrangement of a number of individual adjustment elements, which normally are the same. Thus, a number of rotatable elements allocated to different outlets or passages can be arranged on a disc that is provided with the outlets, with one or more of the elements closing the respectively allocated outlets with other respectively allocated outlets being left open. The ratio of open and closed outlets, determines the effective cross-section of the ventilation channel. The arrangement for throttling or closing the ventilation channel can be mounted along the ventilation channel and at one or both ends.
An advantage of the inventive hearing aid device is that the cross-section of the ventilation channel can be adapted to the respective acoustic situation in a fast and simple manner. Neither tools nor a second person are necessary for adjusting the hearing aid device worn in the ear.
Normally, a relatively large cross-section of the ventilation channel is selected in order to guarantee optimal wearing comfort. In the case of particular acoustic situations, for example in a silent sound environment with simultaneous high amplification by means of the hearing aid device, the cross-section of the ventilation channel is reduced or, respectively, closed. In this way, feedback via the ventilation channel can be avoided.
There are other situations in which it is advantageous to constrict or close the ventilation channel. For example, if the hearing aid device allows functions such as directional effect or background noise reduction, the acoustic bypass, which the ventilation channel represents vis-a-vis the electrical signal path, has a negative effect on these functions. In these cases as well, its negative influence on the cited functions can be suppressed by constricting or closing the channel.
The arrangement for constricting or closing the ventilation channel is inventively operated by electrical and/or magnetic miniature drives. The simple operability and the accurate adjustability of the cross-section of the ventilation channel are advantages that result therefrom. Electrical switches, key buttons, rotating actuators etc. can be utilized as operating elements. The operating elements can thereby fulfil a number of functions at the same time and, apart from the adjustment of the ventilation channel, also can influence the parameters of the signal processing. In an exemplary embodiment of the invention, for example shifting the volume control toward a higher amplification at the same time leads to a reduction of the cross-section of the ventilation channel.
In a version of the invention, a remote control is used for operating the arrangement for constricting or closing the ventilation channel.
In a hearing aid device with a number of hearing programs, the position of the element for constricting or closing the ventilation channel is preferably coupled with (set by) the currently selected hearing program. Thus, the cross-section of the ventilation channel is also automatically adjusted corresponding to the requirements of the selected hearing program when the hearing program is changed.
In an embodiment of the invention, the arrangement for constricting or closing the ventilation channel can be set by the hearing aid device. For example, a basic adjustment of the arrangement is set in a way that is convenient for the operator when the hearing aid device is adapted to the person wearing it.
In another embodiment of the invention the signal processing unit controls the adjustment of the element for constricting or closing the ventilation channel. For this purpose, the signal processing unit analyzes and evaluates the current acoustic environment by means of a suitable algorithm and controls the corresponding adjustment of the cross-section of the ventilation channel. Detection and avoidance of the acoustic feedback channel by the ventilation channel can be included in this evaluation.
In an embodiment, the ventilation channel has a number of homogenous (i.e. identical or very similar) elements for constricting or closing the ventilation channel, these elements being arranged in parallel. Preferably, these elements are arranged on a common carrier and can be separately driven, so that some of these elements open outlets through the carrier, while others close corresponding outlets. The ratio between open and closed outlets determines the effective cross-section of the ventilation channel.
Expediently, the last described elements are manufactured by micromechanical techniques. For the micro-structuring, lithography and etching techniques, which are known from semiconductor technology, as well as other methods, such as the LIGA-technique, can be utilized. LIGA is an abbreviation for lithography, electroforming and shaping techniques. Very small three-dimensional structures can be produced with such micromechanical techniques and can be combined to form the arrangement for constricting and closing the ventilation channel. The generation of power for operating these elements is based on various principles, such as the piezo-effect, the shape memory effect or on electrostatic forces. Such production techniques lead to a cost reduction given a large scale manufacture, in particular.